Method of conditioning molten



n cenone Jovlyvai, 194s nsrnonor oosnronnvo noem necomme suora maoaavrmo f meme .Campana Reading. of Pennsylvania,

V rr'anoa o'Noiu wymo,

alaignm No proving. Aopuosuon nooomtor'is, im.

Reading. la.. aeslgnos'. byl uit'. 't0 m com Pa., a banking institution soi-iol No. mais "s claims. (cms-isi y" l'Ihis'inve'ntion lrelatos to metallurgy and more particularly to the metallurgy of beryllium-copper metal. The omen blow is `continued for an eix-v alloysiand has for its object the provision oi an tended time interval while the temperature ofthe y eilectivve method oi' eliminating gases and undismolten metal'ialls and is terminated before the solved-oo cluded matter from molten beryllium- I temperature of the molten metal drops toa temcopper alloys.`

f Another object isto provide an eilective method voi purifying molten beryllium-copper alloys.'

AStill another object is to provide a methodl of conditioning `molten beryllium-copper alloys for l0 casting into sound ingots.

Other obiectsand advantages will be apparent as the invention is hereinafter more fully disclosed.

In accordance with these objects Il havedislo covered that, contrary to expectations, molten beryllium-copper alloysmay be completely degasitled and freed of undissolvedoccluded matter by super-heating the alloys to temperatures within the range Al90i'i"2400" Be content and melting point of the 13e-containing alloy being treated. blowing oxygen therethrougmand then deoxidizing the-melt before the temperature oi the melt falls to atemperature below about l900 F., without occasioning any appreciable loss of beryllium in the alloy. By the term super-heating" is kmeant heating `to temperatures materially above the melting point o! the alloy which varies with respect to the Bccontent as one skilled in the art will recognize. `In the manufacture of beryllium-copper alloys, particularly the low beryllium content alloys con taining beryllium within the range .3 to 3.0% it is exceedingly diilicult to obtain a gas'and occlusion- F.. depending on the In o's to vigorously agitato the super-hosted molten perature approxlm'atinl 1900 1*'. 1

The dross `and ofi and asumcient amount deoxidation to proceed to completion and it a trial casting indicates the metal is ready for castscrap material and is 'also of particular utility in' 85 the forming of beryllium-copper alloys viromcopper and beryllium-copper master alloy. In the forming of beryllium-copper alloys by the general y method oi diluting a beryllium-copper master alloy with' copper until the desired beryllium content is obtained,considerable diillculty is experienced in eliminating dross and non-metallic ocv clusions from the molten metal. Where the masfree cast ingot suitable for mechanical reduction 3.3

to sheet, bar. rod and wire sizes. The usual foundry practices applied to copper alloys generally to eliminate gases and occlusions are not applicable to beryllium-containing copper alloys and accordance with the present invention, however, even extremely dirty and gassy metal may bequickly and effectively freed of dross and other suspended or occluded undissolved impurities and v usually result in material losses of beryllium. In 40 completely degasliled and placed in condition for 45 casting into sound workable lnBOtS.

.As an example oi' the present invention, the beryllium-copper alloy to be treated by the present invention is -brought to the molten condition in a covered crucible in a reducing or neutral atv5U mosphere as is customary in the art. The molten alloy is then super-heated to a temperature within the range 1900240il F., and with the furnace heat turned oil?, substantially pure dry oxygen is blown vthrough the molten metal at such arate 55 ter alloy has been prepared by the arc-furnace method described and claimed in Gahagan Patent No. 2,193,482. dated March l2, 1940; which patent is assigned to the same assignee as the present application. the master alloyufrequently contains beryllium carbide, nitride and oxide occlusions as well as dross and substantially inert material such as silica sand. The copper employed in diluting the master.alloy frequently contains large amounts of copper oxide and gases,

such' as hydrogen.

When substantially pure dry oxygen .is passed through beryllium-copper alloys at temperatures above about 1900 F.. the beryllium content of the alloy, particularly in the presence of hydrogen dissolved in the metal. appears substantially unaffected by the oxygen. the reaction appearing to go in the direction to form H-OH rather than inthe direction to form BeO. At temperatures below 1900 F., however, the reaction appears to be reversed and the beryllium losses incident to oxidation are relatively'high.

Having hereinabove describedv the present ininsoluble material over. the` surface oi' the molten metal lsthen quicklyfskimmed ot'a deoxidizer agent consisting at least in part-.oran alkali or valkaline earth metal, such as lithium-copper or lcalcium I boride. is added to the moiteng-,alloynto effect a removal oi.' the oxygen and'inetfal'oxides'present, n in the molten metals-'Themoltenvmetal isallowed to remain quiescent i'or a time interval to permit 2 assenso v cntion generically and specically and given one specic embodiment of the same itis believed apparent that the same may be widely vvaried witht out essential departure therefrom and ally such modifications and departures are contemplated as may fall within thescope' of the 4followingf claims. v

what I claim is:

1. The method of preparing molten berylliume copper alloys for casting which comprises'heating the molten metal to temperatures materially above the melting pointof the alloy. blowing the molten metal with oxygenior a time interval at least sufiicient to eliminate therefromvsubstantially all ofthe hydrogen content thereof. maintainingy the alloy throughout the oxygen blow at a temperature in excess of about 1900 F., and demodi-.liz the blown molten metal .with a deoxidizer agent comprised atleast in part of a metal of the group consisting of the alkali and alkaline earth metals before castirmr and solidii'ying the alloy.

2, In the melting and casting of copper alloys containingberyilium as one alloy constituent, the method of conditioning the molten alloy for castine'` which comprises super-heating 'the' molten 'alloy to a tempera-ture 'within the range 1900 2400' F., blowing oxygen through the superheated alloy for a tinieinterval at least sulcient to remove substantially all of thethydrogen content thereof and to Abring to the surface' of the alloy 3 substantially all of the dross and undissolved forign matter suspended therethrough; and then deoxidizing the alloy with a deoxidizer agent com- 1o F.. blowingjoxygen throughthe molten alloy for a time interval at least suiilcient to eliminate the hydrogen content of. the alloy and to provide a' might excess of dissolved oxygen in the alloy. and then deo'xidizing the molten alloy by appropriate additionsof 'a metal of the alkali and alkaline earth metal group.A

The method o( conditioning:` molten beryllium-containing copper alloys for casting which lcomprises super-heating' the alloy to tempera- 20 tures within the range NOW-2400" F., blowing oxygen eas therethrough while maintaining a temperature above about i900- F., for an extended time interval at least suieient to lprovide for the collection of substantially' all of the occiuded insoluble and non-oxidizabie impurities of the metal into a surface dross and for the oxidation of substantially all'of the occluded insoluble and oxidizable impurities ofthe metal into a surface dross l and for the oxidation of substantially all hydrogen contained in .the molten metal, removing the surface dross and deoxdizing the molten metal bath with appropriate additions oi a metal i the alkali and alkaline earth metal groups before casting. FRANCIS ONEILL WYLLIE. 

